<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Way1</title>
	<script type="text/javascript">
		var num1=1;
		var num2=2;
		var num3;
		var num3=num1;
		var num1=num2;
		var num2=num3;
		console.log(num1);//2
		console.log(num2);//1
	</script>
</head>
<body>
	
</body>
</html>